Combined traditional Chinese medicine therapy for the treatment of infertility with polycystic ovary syndrome: A network meta-analysis of randomized controlled trials

Background: Polycystic ovary syndrome (PCOS) infertility has attracted great attention from researchers due to its high incidence. Numerous studies have shown that Chinese medicine is effective in treating this disease, but there is a wide variety of Chinese medicine therapies available, and there is a lack of comparative evaluation of the efficacy of various Chinese medicine combination therapies in the clinic, which requires further in-depth exploration. This study aims to evaluate the efficacy of a combined traditional Chinese medicine (TCM) therapy for the treatment of infertility with PCOS using network meta-analysis (NMA). Methods: In PubMed, web of Science, Cochrane Library, Embase, China Knowledge Network, Wanfang Data, VIP Database, China Biomedical Literature Database (SinoMed) databases, searchs were conducted for information about the randomized controlled trials (RCTs) of combined TCM therapy for the treatment of infertility with PCOS. Quality evaluation was performed using the Cochrane 5.3 risk of bias assessment tool, and NMA using Stata 16.0. Results: This study comprised 28 RCTs using 8 combined TCM therapies in total. The results of the NMA showed that moxibustion + herbal, fire acupuncture + herbal, acupuncture + herbal, electroacupuncture + herbal, and acupoint application + herbal improved the clinical pregnancy rate better than acupuncture, herbal, and western medicines monotherapy (P < .05). Additionally, ear point pressure + herbal enema + herbal, acupuncture and moxibustion + herbal, fire acupuncture + herbal, and acupuncture + herbal improved the ovulation rate better than acupuncture, herbal, and western medicines monotherapy (P < .05). Moxibustion + herbal, fire acupuncture + herbal, and acupuncture + herbal are the 3 most effective therapies for improving the clinical pregnancy rate. Fire acupuncture + herbal, acupuncture + herbal, and ear point pressure + herbal enema + herbal are the 3 most effective therapies for improving the ovulation rate. Conclusion: The combined TCM therapy demonstrated better efficacy for the treatment of infertility with PCOS compared to acupuncture, herbal, and western medicines monotherapy. However, the optimal treatment therapy varied depending on the outcome indicators. Further large sample, high-quality, and standardized RCTs are needed to verify these findings.


Introduction
Polycystic ovary syndrome (PCOS) is a clinical condition characterized by hyperandrogenism, oligoovulation, and polycystic ovarian morphology. [1]It is among the major challenges of modern society, with a complex etiology, and is a common gynecological disorder that significantly impacts the reproductive health and quality of life of women of reproductive age.
The estimated prevalence of PCOS before menopause is 1 in 10 women, ranging from 5% to 15% depending on ethnicity, and affects 7% to 15% of women of reproductive age.[4][5] Infertility due to PCOS accounts for approximately 30% of all female infertility cases and is the leading cause of anovulatory infertility. [6,7]The World Health Organization predicts that infertility will be among the top 3 common diseases in the 21st century following tumors, cardiovascular, and cerebrovascular diseases, with a global prevalence rate of 8% to 12%. [8,9]It has been reported [10] that in China, the number of infertility patients has exceeded 50 million accounting for about 15% of women of reproductive age.The decline in female fertility due to aging will present numerous challenges to the country's economy and society.Therefore, infertility caused by PCOS has become a significant research topic.
For the management of infertility PCOS in clinical, western drugs typically employ drugs such as letrozole, clomiphene citrate, and clomiphene.13] Alternative, non-pharmacological treatment options such as ultrasound-guided follicular puncture and laparoscopic ovarian drilling also entail certain risks and may lead to postoperative complications like periovarian adhesions and ovarian hypoplasia. [14]While assisted reproductive technologies are already in clinical use, such as intrauterine insemination and in vitro maturation culture of immature eggs are available, their efficacy remains a matter of debate; and often lead to high ovulation rate, low pregnancy rate, high miscarriage rate. [11,15][18] Traditional Chinese medicine (TCM) therapies such as herbal formulas, herbal extracts, and acupuncture have become increasingly important interventions for the prevention and treatment of PCOS according to extensive data analysis. [19]29][30][31][32] However, TCM therapies are diverse and have varying efficacies.Conventional meta-analysis methods can only achieve pairwise direct comparison between single therapies.As a result, the lack of comparative evaluation of multiple TCM combination therapies hinders clinicians in clearly judging their therapeutic value.This limitation is detrimental to the exploration of the maximum advantages of TCM combination therapies and the selection of optimal treatment solutions.[34][35][36][37] Therefore, this study aimed to search for randomized controlled trials of TCM treatments for PCOS infertility in recent years both domestically and internationally.We will utilize NMA to mine optimal treatment solutions for this disease.The objective of this is to provide a reliable evidence-based foundation for clinical application.

Registration
The protocol for this systematic review and NMA is based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocols. [38]This protocol has been registered with PROSPERO (registration number: CRD42023410217).

Ethics approval and consent to participate
Such as: ① sporadic ovulation or anovulation; ② clinical evidence of hyperandrogenemia and/or high androgen levels; ③ presence of polycystic ovaries on ultrasound (one or both ovaries having more than 12 follicles with diameters ranging from 2 to 9 mm and/ or an ovary volume >10 mL).(Note: the above conditions meet 2, and exclude other diseases such as congenital adrenocortical hyperplasia, Cushing syndrome, etc).The diagnostic criteria for infertility were in line with the definitions outlined by the World Health Organization, Obstetrics and Gynecology, [40] or Gynecology of Traditional Chinese Medicine, [41] such as a current and uninterrupted sexual life for over a year without contraception and no conception.There were no limitations concerning the age, duration of illness, or source of the cases of the included patients.

Interventions. Trial group:
The combined application of TCM compounds, acupuncture, and other therapies based on TCM theory and meridian and acupoint theory is allowed, with no restrictions on the intervention start time, treatment duration, Chinese herbal selection, or acupoint selection.Control group: conventional western medicines such as Letrozole, Clomiphene, and Metformin, placebo (sham acupuncture), or one of the combined therapies (as used in the trial group).

Outcome indicators.
The following outcome indicators were considered: ① clinical pregnancy rate; ② ovulation rate.

Exclusion criteria
Studies that met the following criteria were excluded: ① studies with unclear or undefined diagnostic criteria.② Duplicate studies published in multiple languages or formats, such as journals and conferences.③ Studies that include patients with infertility not solely attributed to PCOS or those with multiple pathologies.④ Non-RCT trials, animal studies, reviews, systematic evaluations, and meta-analysis.⑤ Studies that lack complete data and cannot be remedied by contacting the authors.⑥ Studies that demonstrate noncompliance with intervention.⑦ Studies that lack endpoint indicators related to infertility with PCOS.

Retrieval strategy
The search strategy adopted a combination of subject and free words.We will use computers to search 8 databases, including PubMed, Cochrane Library, Web of Science, Embase, China Knowledge Network, Wanfang Database, VIP Database, and Chinese Biomedical Literature Database (SinoMed) from build database until February 28, 2023.Subject terms and free terms were utilized in a joint search, based on the characteristics of each database, and the search formula was developed and adjusted accordingly.The search terms include: "acupuncture," "Traditional Chinese Medicine," "polycystic ovarian syndrome," "infertility," et al Taking PubMed as an example, the search strategy is provided in Table 1.

Literatures screening and data collection
Two researchers independently conducted a thorough literature review, extracted pertinent information, cross-checked for accuracy, and established a comprehensive database.Disagreements regarding the literature were resolved through consultation with other qualified researchers.EndNote (V.X.9.2) software was used for screening literatures: ① delete duplicate literature; ② read the title and abstract to exclude literature; ③ read the full text for secondary screening according to inclusion and exclusion criteria.(Full text information could be obtained by e-mail and other means of authors if needed during the screening process.) Data collection: ① title, author, publication time, etc; ② baseline characteristics and interventions; ③ elementary risk of bias evaluation indicators; ④ outcome indicators measurements data.

Assessment of the risk of bias
Risk of bias was evaluated according to the quality evaluation tool (RoB 2.0) recommended in the Cochrane Handbook 5.1.0. [42]The assessment was conducted by 2 investigators independently, cross-checked, and any discrepancies were resolved through discussion with the other investigators.Evaluation contents: random sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting, and other possible biases.According to the criteria, each item was judged as "low risk," "high risk," or "unclear risk."

Statistical analysis
The outcome indicators in this study were all dichotomous variables, and utilized odds risk (OR) as the effect size, and its 95% confidence interval (CI) was calculated.Taking into account inter-study heterogeneity, the data were analyzed using a random effects model. [43]NMA was conducted using Stata 16.0 software by using the network package command.The evidence network diagram depicts the number of patients who received the intervention, with larger dots indicating more significant numbers, while the thickness of the line between 2 interventions represents the number of studies included. [44][47] In addition, a "comparison-corrected" funnel plot was used to assess the publication bias and small sample of included studies. [48] Results

Results of study identification and selection
Through a rigorous search of diverse databases, a total of 4168 articles were initially identified.This consisted of 978 articles sourced from China Knowledge Network, 875 articles retrieved from Wanfang Database, 661 articles obtained from VIP Database, 1020 articles obtained from SinoMed, 57 articles retrieved from Cochrane Library, 293 articles obtained from Embase, 52 articles obtained from PubMed, and 232 articles obtained from Web of Science.Following meticulous evaluation of the title and abstract, 1699 articles were excluded, leaving only 28 RCTs  for further assessment and meta-analysis. The screning process and results for this stage are depicted in Figure 1.

Quality assessment of the included studies
We assessed the risk of bias for each study using the Cochrane RoB-2.0 tool.] used sequence of medical visits, one study [52] used treatment methods, both in non-randomized grouping, rated as "high risk."Meanwhile, 8 studies [51,55,56,58,60,65,67,71] mentioned randomized grouping, but failed to specify the specific way of generating the randomized sequence, rated as "unclear risk."None of all studies  mentioned whether allocation concealment was performed was evaluated as "unclear risk."None of all studies  mentioned the use of blinding for patients, intervention implementers, data analysts, and outcome assessors, which was evaluated as "high risk." In 4studies [61,62,68,72] detailed information concerning shedding rates and reasons for missing cases were reported, the missing data were insufficient to affect the predicted intervention effect therefore classified as "low risk"; and the remaining were rated as "unclear risk."None of all studies  mentioned clinical study registration information, and the complete study protocols were not available hence classified as "unclear risk."There was no mention of other biases within any of the studies,  which were categorized as "unclear risk." The valuation table for risk of bias is depicted in Figure 2.

Network meta-analysis
3.5.1.Pregnancy rate.The NMA of the yielded studies resulted in 55 pairwise comparisons.By combining the OR and 95% CI, the NMA results revealed that MH, FH, AH had better intervention effects compared to AMH, A, H, and W. Additionally, EAH showed better efficacy than W, and AAH showed better efficacy than H.All of the above differences were statistically significant (P < .05).No statistically significant differences in the comparisons (P > .05)were observed between the other interventions, as demonstrated in Figure 4.

Ovulation rate.
The NMA of the included studies yielded 36 pairwise comparisons.Combining the OR and 95% CI, the results of NMA showed that MH had better efficacy than W and EHH; compared with W, H, the intervention effect of EHH, and AMH was better.Furthermore, FH and AH showed better efficacy than W, H, and A. All of the above differences  were statistically significant (P < .05).Conversely, there were no statistically significant differences in the comparisons (P > .05) between the other interventions, as illustrated in Figure 5.  7.

Publication bias
In the comparison-corrected funnel plot, the dots in the funnel chart of different colors represent direct comparisons between different therapies, with the number of dots indicating the number of studies.
Regarding the pregnancy rate outcome indicators, which consist of 12 distinct comparison groups for the interventions, most of the dots in the funnel plot were symmetrically distributed on the vertical line and its corresponding sides.However, the scatterplot of the points indicates the possibility of some degree of publication bias (Fig. 8A).Regarding the ovulation rate outcome indicators, which comprise 8 distinct comparison groups for the interventions, most of the dots in the funnel plot were symmetrically distributed on the vertical line and its corresponding sides.However, one group stands out as being further away from the regression line, suggesting the presence of some degree of publication bias (Fig. 8B).

Results analysis
The findings of this study demonstrate that moxibustion + herbal, fire acupuncture + herbal, acupuncture + herbal, electroacupuncture + herbal, and acupoint application + herbal have some degree of advantages when exhibited improved the clinical pregnancy rate among PCOS-related infertility in comparison to monotherapy involving acupuncture, herbal medicine, and western medicine.Moreover, ear point pressure + herbal Enema + herbal, acupuncture and moxibustion + herbal, fire acupuncture + herbal, and acupuncture + Chinese herbal medicine also have some degree of advantages when enhanced ovulation rate in PCOS-related infertility compared to monotherapy comprising of acupuncture, herbal, and western medicine.When combined TCM therapy was used as alternative therapies, the cumulative probability ranking suggested that the top 3 efficacies in terms of improving pregnancy rate were moxibustion + herbal, fire acupuncture + herbal, and acupuncture + herbal, and the top 3 efficacies in terms of improving ovulation rate were fire acupuncture + herbal, acupuncture + herbal, ear point pressure + herbal enema + herbal.In summary, it is evident that the optimal treatment programs varied based on the outcome indicators, and there was no optimal treatment program for each outcome indicator.
In the TCM, there is no specific term for PCOS, but based on its clinical symptoms, it can be classified as "amenorrhea," "lower abdominal masses," "infertility," "scanty menstruation," and so on.Due to the complexity of PCOS, Chinese medicine experts have varying opinions on its etiology and pathomechanism, but generally agree that it can be treated through regulating the functions of the kidney, spleen, and liver.Previous studies, when statistically analyzing the TCM syndromes of PCOS, showed that kidney deficiency is the main syndrome of PCOS and has the highest frequency of occurrence. [53]On one hand, kidney essence insufficiency can lead to the inability to nourish the tiangui and affect the development and maturation of the ovum.On the other hand, kidney essence insufficiency can involve the functions of the liver and spleen, generating phlegm-dampness and blood stasis, hinder the function of the Chongren, uterus or skin, causing difficulty with the discharge of ovums and symptoms such as hirsutism, obesity, and acne.It can be seen that this disease is based on kidney deficiency, involving the liver and spleen, phlegm-dampness and blood stasis as the target, interacting with each other, disrupting the dynamic balance of the reproductive axis of "kidney -tiangui -Chongren-uterus" and causing metabolic dysfunction of the body, thus affecting women's pregnancy and impregnation in addition morbidity. [77]gure 4. Network meta-analysis of the pregnancy rate.
As an adjunctive therapy, TCM can offer personalized treatment from a holistic perspective combining pattern differentiation and treatment.Recent research has indicated that TCM effectively manages PCOS through herbal formulations and acupuncture. [78]Modern pharmacological examination has validated the efficacy of many herbal monomers.[81][82] The most common cycle-regulating therapy in TCM can regulate menstruation and promote ovulation through the patterns of qi and blood and yin-yang changes and the administration of medication at different stages. [83]Its mechanism is being gradually explored.Xu et al [84] discovered that adjusting the weekly cycle method can improve local microcirculation in PCOS patients, increasing blood supply to the uterus and ovaries, promoting follicle development, and ovulation.Shen et al revealed that this method can also reduce serum levels of LH, LH/FSH, hirsuteness, and acne incidence while improving ovulation rate. [85]Acupuncture treatment can support the body, improve kidney function, strengthen the spleen, and regulate qi and blood flow by selecting appropriate acupoint pairings, such as Sanyinjiao (SP6), Guanyuan (RN4), Zigong (EX-CA1), Zhongji (RN3), and Qihai (RN6). [86]Additionally, acupuncture can be tailored to address specific symptoms by adding or subtracting acupressure points.Biologically, acupuncture can regulate hypothalamic function, pituitary neurotransmitter release, and ovarian function, which in turn adjusts hormone levels and the uterine microenvironment. [87,88]Animal  experiments have illustrated that electroacupuncture can stimulate homeostasis of the hypothalamic-pituitary-ovarian axis in normal female rats and regulate levels of gonadotropinreleasing hormone, luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone. [89]Furthermore, acupuncture may improve follicular maturation in patients with PCOS by modulating ovarian innervation and decreasing elevated levels of nerve growth factor in the ovaries, in order to achieve the desired therapeutic effect. [88,90]n summary, TCM has shown significant efficacy in treating PCOS.Although there are numerous therapies with significant efficacy, the adverse effects of the drugs limit their clinical applicability.Specific molecular studies and toxicology tests of Chinese herbs are still lacking and require further clarification to provide effective targeted therapy for PCOS.Nonetheless, the interventions mentioned above provide some reference for clinical application and research.Please note that the probability ranking results are for reference purposes only.

Strengths and limitations of this study
Strengths: The literature screening was focused on minimizing differences by focusing on diagnostic, inclusion, exclusion, and efficacy criteria of the included studies.This study selected commonly used TCM therapies to treat PCOS infertility, which expands the range of treatment options, compares interventions, and explores targeted and efficient therapies.
Limitations: The number of outcome indicators in this paper is limited, and the number of RCTs included under different interventions is small.The overall quality of the RCTs included in this paper is not high, and most of the literature did not use allocation concealment methods and record case shedding, which may impact the evaluation of results.The types of Chinese medicine symptoms, the start time of the interventions, and the intervention course of the included studies are inconsistent, which may result in differences in outcome measurements.The included studies examined different types of Chinese medicine symptoms about PCOS infertility, and subgroup analyses could not be performed due to limitations in the literature.A majority of the studies included had small sample sizes, and there was limited utilization of blinding methods with concealed allocation.Blinding is a critical component in reducing potential biases in results, especially for subjectively measured outcomes.While achieving complete double-blinding or triple-blinding designs in acupuncture studies may be challenging, blinding of acupuncture subjects or data collectors or evaluators can help minimize subjective factors and result biases.Additionally, partially randomized patient preference clinical trials may be an effective approach to address these limitations. [91,92]3.2.Adverse reactions.Adverse events play a critical role in clinical trials as they provide important safety information for evaluation.To ensure objective and accurate data collection, future studies should document adverse events in accordance with the clinical protocol.

In terms of diagnostic and efficacy criteria.
The included studies lacked uniform diagnostic reference criteria.In future research, it would be beneficial to establish validated diagnostic criteria based on existing literature or guideline recommendations to enhance measurement accuracy and promote comparability with other studies in the field.
In conclusion, future research should adhere to the requirements of controlled trials, rigorously control diagnostic criteria, reference previous studies or guideline outcome indicators for assessment, design and implement large-scale trials, and faithfully record adverse reactions and safety assessments to achieve higher-quality RCTs.

Conclusions
This research has demonstrated that the combined TCM therapy was effective in improving clinical pregnancy and ovulation rate when used as an alternative treatment for PCOS infertility.Moxibustion combined with herbal may become the optimal therapy to improve pregnancy rate, and fire acupuncture combined with herbal may become the optimal therapy to improve ovulation rate, which has some clinical reference value.In clinical application, the results of this study can be appropriately referred to and appropriate therapies can be selected according to the specific conditions of patients.However, it is important to acknowledge that further research is necessary to verify these findings via large samples RCTs that are of high quality and standardized in nature.

Figure 5 .
Figure 5. Network meta-analysis of the ovulation rate.

Figure 7 .
Figure 7. SUCRA of the ovulation rate.SUCRA = surface under the cumulative ranking.
2.3.1.Research types.This study aims to collect all randomized controlled trials (RCTs) on the combined Chinese Medicine Protocol for infertility patients with PCOS.There are no language restrictions.2.3.2.Research participants.The enrolled patients were definitively diagnosed with infertility caused by PCOS, in compliance with the Rotterdam criteria which was proposed by the European Society of Reproduction and Embryology and Autonomous Sensory Meridian Response in 2003.

Table 2
List of basic features included in the study.